1. Field of the Invention
The present invention relates to a filament winding apparatus.
2. Description of Related Art
There is a known technique for manufacturing a high-pressure gas tank, called filament winding method (hereinafter also called “FW method”). The FW method winds fibers which are impregnated in advance with a thermosetting resin (hereinafter also called “resin-impregnated fibers”) on a liner as a core of a high-pressure gas tank, and thermally cures the thermosetting resin to manufacture the high-pressure gas tank. Employing the FW method allows formation of the high-pressure gas tank having a high-strength fiber reinforced resin layer formed on the surface of the liner. In fabrication of the high-pressure gas tank by the FW method, a filament winding apparatus (hereinafter called as “FW apparatus”) is widely used to wind fiber bundles of the resin-impregnated filaments on the liner of the tank. For example, JP2007-190697A describes a FW apparatus having a wind-up assembly, which includes a fiber-bundle guide assembly configured to be movable relative to the liner of the tank to guide the rein-impregnated fiber bundles, and serves to successively wind the resin-impregnated fibers on the liner. In this FW apparatus, the resin-impregnated fibers with an appropriate tensile force are successively wound on the liner by the fiber-bundle guide assembly, which includes a tension roller configured to apply the appropriate tensile force to the resin-impregnated fibers, and a load measurement unit configured to measure a reactive force applied to the tension roller by the resin-impregnated fibers. The fiber-bundle guide assembly has a widening roller in a drum-like convex shape configured to apply a tensile force to each of a plurality of bundles of the resin-impregnated fibers drawn by the fiber-bundle guide assembly both in a length direction of the fibers and in a width direction perpendicular to the length direction, a narrowing roller in a concave shape configured to unspread the plurality of bundles of the resin-impregnated fibers passing through the widening roller and reduce the interval between the adjacent bundles of the resin-impregnated fibers, and an adjustment port configured to guide the plurality of bundles of the resin-impregnated fibers passing through the narrowing roller to the liner.